Mixer



Dec. 23, 1941.

. E. SCHMIDT MIXER 2 Sheets-Skeet 1 Filed Nov. 1, 1940 Dec. 1941- E. SCHMIDT 2,267,341

MIXER Filed Nbv. l, 1940 2 Sheets-Sheet 2 a l i Fig; l is a viewlargely inlongitudinal section of v a: mixer embodying this invention;

Patented Dec. 23, 1941 sures V PATENT oFFrcE s MixEn Edward Schmidt, =Methuen",fMas s;,' assignor to:

Lawrence Pump and 1 Engine Co Lawrence; Massgracorporation of Massachusetts ApplicationNovember 1, 1940, Serial No. 363,828

I :5r0laims.

M This invention relates tocan improvement in a mixer and more particularly in a 'mixer of'the type shownin my Patent No. 2,206,266, dated July 2, 1940, 'Su'ch mixers havemany. uses as toiblend, di-

lute, disperse,"dissolve or emulsify liquids oroth'er .fluid material wherebylcomplete homogeneity is jobtained. For convenience in description the term.hmixingis used in the, general sense to denote any such "function of a machine of'this ".(The primary object of this invention is to provide a mixer wherein a shearing, action is setup to reduce any lumps in the treate'dmaterial to a minimum! and. thereby. promote a fine degree,

Lemuls'ification. l l v,

Another object of this invention is to provide a mixer having an impeller which; corn- ;pi"ises an annular disk having vanes on opposite surfaces and 'a casing which encloses said "impeller andlhas a .plurality. of portswhich 'coact with the impell'errin the treatment of li'quids' or jfluids. i I Afurther object'of this invention resides in the formation of such casing. with anannular passagelhavingaconverging walls in which passage the disk rotates. and through which passage the li'ciuid 'orvfluidtravels' under the urge of the impeller toward the ports of the casing, the walls of suchwpassage coacting with the disk to set up a a shearing. action by which any; lumps or coarse particles in the liquid are reduced to a minimum.

These'andv other ob'jects of: the, invention will appear from a considerationioffthefollowing description and of .thefaccompanying drawings in Figs' Z'Llandi 3 'are cross-sectional views taken jalonglfth'e sectionlinesi 2 -2and s 3 respectively 7 :Figs. 4 and 5illustrate the top and bottom respe'ctiv'ely offthelimpeller which forms oneelement oflt'he mike-r shown in Fig. 1;

"Fig; dis .a crossesectional'view of such impeller;

I Fig. .lis a sectionalview of the lowerend of anothertype of Imixer. embodying this invention;

frame; renames-5 a pair of posts I I; a casing- 13 which encloses the "impeller anda plate I9 pro-' jecting'ffrom the casinglBi The posts lT ar-e connected at-the lower endshyan-integral cross strap having a bearing 2 I -for the spindle I l. The casing 18 comprisesacove'r n, integral with the crossstrap 20, and'a base 23'; integral with the plate l9," which cover and base coact to tor-m a chamber 24 for the impeller l5; The impeller |5"compri'ses an annular disk 25 which is conical in ycross sectionand upon the faces'of which are jmounted vanes 26-and 2 1'. A collarj28 supported-bythe vanes 23'receives the I lower,'end oithespindlev H to which it is secured bya set screw} 9: As shown in the drawings, the disk25,, cthe"vanes 26 and 21; and the collar 28 arfintegral-andjiormed as a unit; It will -b e understood; however, that if desired the various parts may be separately formedand thereafter assembled to form thehimpeller'. As shown particularly' in Figs. 4 and 5' thevanes 26'and '2'lare ja'rcuate having heads at thecentral opening an inthe disk 25 iandconverging side walls;

The cover 22 of the casing 18 includes an annular wall 3| whichsurro'unds the disk 25 of the impeller. Through the wa113l extend a plurality of ports 32separated by partitions 33; The walls of'the partitions diverge outwardly as shown in Fig. '3 sothat the ports extend tan'gentiallyjwith 1respectto the inner face of the wall 3|.

The

liquid enters the chamber *24 through openings 35 formedinthe base 23 ateach' side. of "the plate [9.

I The chamber includesan annular passage 36 which receives the disk 25beyond the vanes 26 andll; The passage 36 is outwardly tapered fan'd'terminates at the wall3l of the cover 22.

ceives the collar 28 .of the impeller.

The mixerl when in use islinserted" into areceptacle or othercontainer (not shown) for the liduidjor fluidto be treated; and is usually supported-at the desired location upon a crossbar secured. to'the frame IS in any suitable manner.

When the impeller is rotated in the direction indicatedbythe'arrows 4] (Figs; 4 and 5) the liquid is drawn into the chamber24Lthrough'theopenings 34 and l 35 and expelled therefrom through the "ports 32. The vanes 26 and 21 act toforce th''lijqllidirltb' the converging passage 36.

"The layers "of liquid closely adjacent the easing walls have obviously a much lower circumferential speed of travel than have the layers of liquid closely adjacent the faces of the disk and as a result a shearing action is set up between the layers which reaches the greatest intensity at the periphery of the disk just before the liquid enters the ports. The liquid discharged from the mixer consequently contains only very small particles, all the large particles having been disintegrated. The impeller not only acts to disintegrate the particles but also acts through the vanes and ports to distribute the particles uniformly. The streams of liquid emerging from the ports 32 are distributed throughout the container, traveling at such speed that they leave the vicinity of the mixer and insure the entry of untreated liquid into the mixer. After a short period the entire body of liquid in the receptacle has been treated by the mixer and brought into a homogeneous and uniform condition.

The openings 35 in the base of the casing are of advantage in that the suction exerted therethrough draws into the impeller the heavier elements of the liquid which would otherwise tend to remain at the bottom of the container. The plate l9 eliminates any possibility that the openings 35 should be closed by resting directly upon the bottom of the container.

The mixer 50 illustrated in Figs. '7 and 8, has an impeller of the enclosed type wherein liquid enters at both sides of the impeller. The impeller 60 is mounted upon the lower end of the spindle 6! which is driven by any suitable means (not shown) such as an electric motor. The casing enclosing the impeller comprises a cover 62, integral with the post 63, which supports the spindle 6|, and a base 64. The cover 62 has a central opening 55 and at its periphery an annular wall 66 provided with a plurality of ports 6! similar in construction and arrangement to the ports 32 of the mixer 10. A second opening 69 is provided in the base 64.

The impeller 60 comprises a base 10. a collar H, an annular disk 12, a ring 13, vanes 14 between the base 10 and the disk '12, and vanes between the disk .12 and the ring 13. Preferably, as here shown, these various elements are integrally connected. but could, if desired, be separately formed and thereafter united. The ring 13 is spacedfrom the collar H and defines therewith an opening 16 in register with the opening 65 and through which liquid flows to the central opening in the disk. The vanes 14 and 15 while greater -in number than the vanes 26, 21 in the impeller l5, are similarin construction and arrangement and hence detailed description and showing thereof are considered unnecessary and will be omitted. The inner faces of the cover 52 and base 64 which define the annular passage 11 in which the disk 12 travels and into which the liquid isidrawn by the vanes, are inclined toward the wa1l66.

The mixer 53 is operated in substantially the same manner as the mixer l0. The liquid under treatment enters through the opening- 65, is forced by the vanes 14 and 15 into the passage 11, and thence through the ports 61 returned to the container and mingled therewith. The disk 12 acts with the walls of the passage 11 to shear the particles of the liquid in the manner described in detail with respect to the mixer l0. Under some conditions, as where a blending of two or more liquids is'desired, it has been found advantageous to introduce one or more of the liquids directly to the impeller through a pipe 18.

The impeller 60 is reversible and may be used in a mixer, as shown in Fig. 9, with the base 10 uppermost and the opening 16 at the bottom. The casing for the impeller in this position comprises a base having a central opening BI and a cover 82 having an annular opening 83 which surrounds the spindle Bl. That the impeller I5 is also reversible is obvious from a consideration of Fig. 1.

While certain embodiments of this invention have been described herein and illustrated in the accompanying drawings, it will be understood that the invention is not limited thereto and that other embodiments thereof may be made without departing from the spirit and scope of this invention as set forth in the following claims.

I claim:

1. A mixer comprising an impeller, a casing therefor, said impeller comprising a base, an annular disk and a ring, and vanes mounted on both faces of the disk adjacent the central opening therein by which vanes the base and ring are connected to the disk, and means for rotating said impeller.

2. A mixer comprising an impeller, a casing therefor, said impeller comprising a base, an an-- nular disk and a ring, and vanes mounted on both faces of the disk adjacent the central opening therein by which vanes the base and ring are connected to the disk, said casing including an annular passage in which said disk travels when the impeller is rotated, and a peripheral wall having ports therein toward which said passage leads, and means for rotating said impeller. l

3. A mixer comprising an impeller, a casing therefor, said impeller comprising a base, an annular disk and a ring, and vanes mounted on both faces of the disk adjacent the central opening therein by which vanes the base and ring are connected to the disk, said casing including an annular passage in which said disk travels when the impeller is rotated, and a peripheral wall having ports therein toward which said passage leads, the walls of the passage being inclined toward said peripheral wall, and means for rotating said impeller.

4. An impeller for a mixer comprising a base, an annular disk and a ring and vanes mounted on both faces of said disk adjacent the central opening therein, by which vanes the base and ring are connected to the disk.

5. A mixer for liquids comprising a rotatable impeller consisting of a base, an annular disk, a ring and vanes mounted on both faces of the disk. adjacent the central opening therein by which vanes the base and ring are connected to the disk, the outer portion of the disk extending beyond the peripheries of the base and ring, a casing for the impeller including an annular passage in which the outer portion of the disk travels when the impeller is rotated to coact with the walls of the passage and shear the particles of the liquid treated by the mixer, and a peripheral wall having ports therein toward which said passage leads, and means for rotating said impeller.

EDWARD SCHMIDT. 

